To do this we propose to implement current diagnostic tools available in the diagnostics of sleep disordered breathing such as polysomnography (PSG), in combination with rhinological investigations with 4-phase rhinomanometry and techniques such as two-way fluid structure interaction (FSI) computational fluid dynamic (CFD) analysis of patients. For olfactory testing we will use standardized smell tests. These examinations in combination will give us a more detailed view of the factors that influence nasal respiration.